Temperature time-control device



July 17, 1928.

A. J. MOTTLAU TEMPERATURE TIME CONTROL DEVICE Filed April 28, 1927 2 Sheets-Sheet Fig.1.

INVENTOR Auqusi J. Mofilou.

' ATTORNEY I July 17, 1928.

A. J. MOTTLAU TEMPERATURE TIME CONTROL DEVICE Filed April 28, 1927 2 Sheets-Sheet 2 INVENTOR vAugus'T J. Monlqu.

WITNESSES:

ATTORNEY Patented July 17, 1928.

UNITED STATES PATENT OFFICE.

AUGUST J. MOTTLAU, or PITTSBURGH, P NSYLVANIA, assreuon To wns'rmenousn ELECTRIC & MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA.

TEMPERATURE TIME-CONTROL DEVICE.

Application filed April 23, 1927. Serial No. 187,284.

My invention relates. to control devices and particularly to such devices whereby temperature control may be effected during a predetermined period of time.

An object of my invention is to provide a temperature time control device that shall be of simple-construction, economically and easily manufactured and installed.

Another object of my invention is to provide means for actuating a control device in accordance with conditions to be controlled.

A further object of my invention is to provide means for rendering an actuating means embodied in the control device inoperative the moment a predetermined condition obtains; and

A further object of my invention is to provide means for rendering an actuating means inoperative for a predetermined period of time and operative during another interval or period and to provide means for maintaining a condition constant during the latter interval.

In practicing my invention I provide means for controllig a source of energy in accordance with a predetermined condition to be produced thereby and a time control mechanism for rendering the said ,means efl'ective during a predetermined interval of time and ineffective during a subsequent interval.

F or a fuller understanding of the device embodying my invention reference should be had to the following description taken in conjunction with the accompanying drawings, in which Fig. 1 is a partially diagrammatic and partially sectional view of circuits and apparatus embodying my invention;

Fig. 2 is the top plan view of a time temperature control device embodying my invention; V

Fig. 3 is a view in vertical section taken on line III-III of Fig. 2;

Fig. 4 is a development view of a cam embodied in the device illustrated in the preceding figures; and

Fig. 5 is a view, in section, taken on line VV of Fig. 2. f

In the drawings, a base is illustrated which comprises a body portion and a cylindrical easing portion 11 integral with the right-hand end portion of the body. The body portion is provided with a plate 12 of insulating material that may be secured thereto in any suitable manner.-

The cylindrical portion 11 with a laterally extending portion towhich a boss 13 having a flange 14 thereonv is formed. Alined with the boss l 3 isfa boss 15 that extends-into the casing portion 11 for a purpose to be hereinafter set forth.

An end wall of the portion 11 is provided with an inwardly extending boss 17 with which a screw 18 V ment. The screw 18 is provided with a circular head having a knife edge 19 thereon, the screw being adapted to be moved inwardly from the boss l7 to any desired position in which it may be locked by means of a lock nut 21 that has screw thread engagement wlth the portion of the screw 18 that extends outwardly from the cylindrical por-. tion 11. r

One end of the cylindrical portion 11 is provided with a cover at 22, that may be secured thereto by means of a screw 23, a graduated scale 24 being laid off along the edge of the cover for a p rpose to be hereinafter set forth. To the boss 13 may be secured a tubular member 25 having a relatively high coelficlent of expansion. As shown, the outer end of the tubular member is provided with a cap or closure member 25 that has screwthread engagement with the inner portion of the tubular member.

Disposed Within the tubular member 25 is a rod 26 having a relatively low temperature coefficient of expansion. An end-portion of the rod 26, of reduced diameter projects through an aperture in the cap 25 and is secured thereto by a pair of nuts 27 that have screw-thread engagement with the rod. The upper end of the rod 26 may be provided with an extension rod 28, which rod extends through the hole 16 in the bosses 13 and 15. The rods 26 and 28 may be secured together by a tongue-and-groove construction and a rods.

To the upper end of the rod 28 is secured a yoke structure 30. The yoke structure 30, illustrated more particularly in Fig. 5, comprises aframe of substantially rectangular shape having'a stud 31 integral with a bottom side 32 of the frame, the stud 31 havhas screw-thread engageis provided -A hole 16 is located in the bosses l3, and 15 pin 29 extending through. the

ing screw-thread engagement with the upper end of the rod 28, substantially as illustrated in the drawin s. An upper side 33 of the frame is provi ed with a tapped hole 34' for a urpose to be hereinafter set forth.

A mem er 35 is disposed between the sides 32 and 33 and is maintained substantially parallel therewith by means of pins 36 that extend vertically between the sldes 32 and 33. The member 35 is permitted to slide along the pins 36 so as to be maintained substantially parallel with the upper and lower sides of the frame. The member 35 is provided with a pair of wedges 37 located adjacent to the ends thereof, the wedges being equipped with'knife edges 38.

In order'that the member 35 may be limited in its upward movement along the pins 36, a screw 39 is provided that has screw thread engagement with the tapped hole 34. The bolt 39 extends outwardly through an aperture 40 in the cover 22 and the upper end of which may be provided with a knurled knob 41 to which is attached a pointer 42 that is adapted to register with I the scale 24.

Since the tubular member 25 has a high tem erature coeflieient of expansion relative y to that of the rod 26,and since one end of the tubular member 25 is fixed to the boss 13, changes in temperature of the tube 25 will cause it to contract or to elongate, depending upon whether the temperature changes are increasing ordecreasing. Therefore, the yoke, carried by the extension rod, will be caused to move accordingly either towards or away from the boss 15 located in the portion 11 of the base. Thus, it is evident that the tubular member 25 and the rod 26 operate as a thermostat.

To substantially the middle of the body portion 10 of'the base is secured a cam 43 that comprises a rotatable disc 44, the disc being di osed directly above the upper surface of t e plate 12. A segment 45 of substantially rectangular section is secured along the periphery of the disc 44. Cooperating wit-h the segment 45 is a movable segment 46 that may be secured in any desired position on the disc 44, as will hereinafter be set forth. I

In order that the cam 43 may rotate in a plane parallel with the body portion 10, a shaft 47 is provided which is centrally located with respect to the disc 44 and extends through the segment 46, the disc 44, the plate 12 and the body portion 10. The portionof the shaft 46 extending through the disc 44 and the segment 46 has screw-thread engagement with a nut or knob 48 in order that the segment 46 may be adjusted to and secured in a predetermined position. The disc 44 may be secured to the shaft by a screw 49 that extends radially from the cir. cumference of the disc 44 to engage the shaft 47 or by other means well known in the art.

The movable segment 46 is provided with a wedge portion 50 and is adapted to move along the inner periphery of the segment 45. As shown in Fig. 4, the lower edge of the wedge 50 may be substantially in the same plane as the upper surface of the disc 44, the portion rising in a counter-clockwise direction to a higher elevation than the segments 45 and 46.

To the segment 46 is secured a strip 50 that projects radially outward from the wedge 50 of the cam, the strip being provided with a segment 52, the inner surface of which travels along the outer surface of the se ment 45. The right-hand end portion of the segment 52 is bevelled from its upper surface to the left towards the upper face of the disc 44 and from its upper and outer edge towards the edge ofthe disc (see Figs. 1 and The segment 46 may be turned in either a clockwise or counter-clockwise direction so that the distance between the raised wedge 50 and the end 53 of the segment 45 or this portion of the-travel of the cam may be adjusted to any desired length.

As illustrated in Fig. 2 of the drawings, the segment 45 and the disc 44 may be graduated into equal divisions which may, if

desired, represent half hours of time and the disc may be so rotated that one complete revolution will take place every twelve hours.

In order that the cam 43 may be rotated at any desired speed or so that it may be caused to make one complete revolution in twelve hours, a motor 54 is provided. The

motor 54 is adapted to rotate the shaft 47 by means of a pinion 55 secured to the motor shaft, that meshes with a gear 56, keyed to the shaft 47. It is to be understood that member 65 extending across the aperture,

the ends thereof being integral with the plate. The plate 64 and the bridging member 65 may be formed by a simple stamping operation whereby a pair of longitudinally extending slots 66 and 67 are provided in a blank sheet of metal. The slots having been provided, the plate may be drawn in a succeeding stamping operation in order to produce depressions 68 of substantially W shape at substantially the middle portion of the sides of the plate and the curved end portions 69 located at the ends of the bridging member. The left-hand end of the plate 64 may be bent upwardly as indicated at 71, for a purpose to be hereinafter set forth.

The metallic plate 64 may be secured to the base 62 by screws 72 and 73, or other equivalents, that extend through the portions of substantially W-shape and through the base 62. Disposed between the screws 72 and 73 is a bolt 74 that extends from the bottom edge of the base 62 to the top edge thereof, the latter being provided with a contact 75 that is adapted to cooperate with a movable contact 76 carried by the bridging member 65. As shown in Fig. 3 of the drawings, the contacts are in disengaged positions. The bolts 73 and 74 comprise the terminals of the switch 61 and may be connected in circuit with an electrical device to be controlled. It is to be noted that the base 62 is provided with end portions that project downwardly below the surface of the stationary contact 75, in order that the contact 76 may be permitted to move from the position in which it is located, as shown in Fig. 3, to a position in which it engagesthe stationary contact.

The right-hand end portion of the switch 61 is provided with a screw 77 that has screwthread engagement with the bracket 63 in order that this end of the plate may be deflected towards the bracket 63 to a predetermined position.

The switch 61 is supported in the position illustrated "n the drawings b brackets 78 and 7 9, th lower portions 0 the brackets being bent at substantially right angles in order to rest flatly upon the upper face of the plate 12, and secured thereto by such means as screws orother equivalents. The base 62 of the switch is disposed between the upper ends of the brackets 78 and 79 and is secured thereto preferably by screws, al though similar devices may be employed.

It the left-hand end of the plate 64 of the switch 61 is bent upwardly to the position illustrated in Fig. 3 of the drawing, the

(ill

bridging member is caused to assume the position as shownf If the deflected end of the frame is released to its unrestrained position, a position substantially horizontal in this case, the bridging member is released and its curvature changed to such an extent that the contact 76 engages the contact 75. The contact 76 moves into and out of engagement with the contact with a snap motion, a motion imparted thereto by the bridging member 65 as either one or the other of the ends of the plate (34 is deflected from a horizontal to an inclined or tion.

In order that the movement of the yoke structure 30. caused by the contraction and elongation of the tubular member 25, may

deflected posibe utilized for actuating the switch 61, a switch actuating mechanism 81 is provided. The switch actuating mechanism 81 comprises a lever 82 and a tail piece 83 secured to the right-hand end. th reof, a fork 84 secured to'its left-hand end and a roller 85 pivlotally secured between the prongs of the or r. 1

The tail piece 83 comprises a bifurcated portion having a raised central portion 86 and depressed side portions 87 (see Fig. 5). The raised portion 86 rests upon the knife edge 19, and the knife edges of the Wedges 37 rest upon the side portions of the tail piece. In order to preclude lateral and longitudinal movement of the lever 82, but not to restrict vertical movement with respect to the base portion 10, a pin 88 is provided that has screw-thread engagement with the base portion 10 and extends upwardly through an aperture 89 in the lever.

Upon an elongation of the tubular member 25, the yoke structure 30 is pulled downwardly, as viewed from Fig. 3,to cause the knife edges 38 to bear upon the side portions of the tail piece 83 and to cause it to pivot on the knife edge 19. It will be evident, therefore, thatthe left-hand end of the lever 82 will be actuated upwardly towards the switch 61. Since the distance between the knife edges 19 and 38 may be made very small, a small change in the length of the tubular member 25 will cause a relatively large movement of the left-hand end of the lever 82. The knife edges and the lever may therefore be considered as a motion multiplying mechanism.

The temperature at which the tubular.

member 25 is effective to actuate the lever 82 to that position required to cause disengagement of the contacts 76 and 7 5 may be varied by adjusting the screw 39 to such a position thatmore expansion is required for higher temperatures in order to actuate the knife edges 38 firmly into engagement with the side portions 87 of the tail piece and less expansion when lower temperatures are required.. It is evident, therefore, that the switch 61 may be actuated to its circuit opening position (see Fig. 3) when the tubular member 25 attains one of a plurality of predetermined temperatures, depending upon the position of the member 35, as limited by the screw 39. By calibrating the scale 24, in terms of temperature, the switch 61 may be caused to operate at, any desired temperature in response to the movement of the tubular member 25.

The cam 43 cooperates with the roller 85 of the switch actuating mechanism 81 in such a manner that when the roller is in contact with the upper surface of the segments 45 and 46, the thermostat, consistin': of the tubular member 25 and the rod 26 is rendered ineffective to actuate the switch desired, the segment 46 is turned in a clock 44 at three oclock.

mechanism 81. When the roller 85 makes contact with the upper surface of the disc 44, or that portion of the cams travel located between the ends of the segments 45 and 46, the lever 82 is permitted to be actuated by the thermostat, from its lower position to the position illustrated in the drawln s.

Assuming that the switch 61 is in a circuit opening position and that it is desired that the switch 61 shall be returned to its circuit closing position at a predetermined time, the disc 44 is turned to such a position that the end 53 of the segment 45 is located in the proper place with respect to a pointer 90. As a concrete example, it may be assumed that the pointer 90 represents 12 oclock andthat the roller 85 shall make contact with the upper surface of the disc 44 is so turned that a mark 90 on the segment 45 coincides with the pointer 90. The disc 44 must then turn for three hours before the roller 85 drops off the end 53 of the segment to engage the upper surface of the disc 44. The thermostat will now be eflective to operate the switch mechan sm 81 to cause the switch 61 to be actuated intermittently to circuit-operating and closing positions until the raised portion of the segment 46 engages the roller 85 to actuate it to the posit'on illustrated in Figs. 1, 2 and 3.

' If it is desired that the roller 85 shall make contact with the upper surface of the disc 44 for a period of four hours the segment 46 is turned in a. clockwise direction until the lower end of the wedge 50 is located four main divisions from the end 53 of the segment 45.' If a shorter period is wise direction until the required number of divisions intervene between the portion 50 and the end 53 of the segment 45. I

If it is desired that the cam 43 shall be utilized merely to fix the time at which the roller 85 makes contact with the upper surface of the disc 44. and that the lever 82 shall be held in the position required to maintain the switch 61 in its circuit-operating position the moment a predetermined temperature obtains in the thermostat, or in a device the temperature of which is to be, controlled thereby, a latch mechanism 91 is provided. r

The latch mechanism 91 comprises a. tubular member 92 having a shoulder portion or flange 93 resting upon the plate 12 and a screw portion 94-extending through the plate and the body'portion 10. The tubular member 92. may be turned in either a counter or clockwise direction. As shown, aportion of the tubular member adjacent the flange 93 is provided with d ametrically opposed elongated slots 95, through which a In this case the disc pin 96 extends. The pin 96 is held towards the position illustrated in Figs. 1 and 3 by means of a. coil spring 97 located within the tubular member but disposed between the pin 96 and the flange 93. The pin 96 may be pressed downwardly towards the flange 93 by means of a pin 98 that extends longitudinally through the tubular member 92 so as to engage the former. The tubular member 92 is provided with a spring 99, one end-of which is anchored to the pin 88 and the other end thereof being secured to a lever 100 that is attached to the screw portion 94 of the tubular member. In order to retain the tubular member 92 in the position illustrated in Figs. 1, 2 and 3, a bracket 101 is provided and so secured to the plate 12 that it straddles the pin 96, the portion of the bracketstraddling the pin being provided with a recess 102 into which the pin is forced by means of the coil spring 97.

The tubular member 92 is provided with a notch or recess 103 that is adapted to engage a resilient detent 104 carried by the lever 82. When the notch 103 and the detent 104 are in alinement, the detent, being resilient, springs into the recess 103' and holds the lever in a raised pos'tion the moment the roller 85 engages the highest portion of the wedge 50, or the highest portion of the cam.

lVhen the tubular member 92 is in the position illustrated in the drawings, the recess 103 isout of position to reg ster with the detent 104. But, if the cam 43 is rotated in a clockwise direction until the beveled portion 52 of the segment 51 engages the pin 96, the pin is pressed downwardly and released from the recess 103. Upon the release of the pin 96, the spring 99 operates to turn the tubular member 92 to such a position that the detent 104 slips into the recess 103. The lever 82 is, therefore, caused tobe held in a position slightly higher than that illustrated in Fig. 3. Until the tubular member 92 is returned to its latched position (see Fig. 1), the lever 82 will be maintained in itsraised position, thereby preventing the switch 61 from returning to its circuit-closing position.

If it is desired that the thermostat shall so actuate the switch 61 that a predetermined temperature is mainta ned in a body to.be controlled and to maintain that temperature for a predetermined length of time, the distance or the travel of the cam between the end 53 of the segment 45 and the portion 50 of the segment 46 is adjusted to the length of time desired. In this case, the latch 91 should be maintained in the posit on illustrated in the drawings. The thermostat will now be effective to operate the switch 61 during the travel hereinbefore mentioned or until the beveled end of the portion ofthe segment 51 engages the pin 96 to effect a release of spring 99 and such a positioning of-the notch 103 that it registers with the detent 104. The lever 82 being restrained from movement, the thcrmostatis rendered ineffective and the switch 61 maintained in its circuit-operatng position until released by the latch 91.

In Fig. 1 of the drawings the device embodying my invention is shown as being applied to the time temperature control of an electrically heated oven 105. The oven may be equipped with aresistor heating element 106 that is connected to the supply conductors 57 and 58 by means of a relay 107 under the control of the switch 61. As shown the terminals of the coil of the relay 107 are connected to the terminals 73 and 74 of the switch 61. When the switch 61 is in the circuit-closing position, i. e., the contacts 7 5 and 76 being in engagement, the coil of the relay 107 is energized to cause contact bridging members 108 to engage cooperating stationary contacts 109 and 110, thereby completing an electric circuit from the supply conductors 5 and 58 through the resistor 106 and the relay 107. The instant of time at which the resistor elements 106 are to be energized may be determined in the manner previously set forth herein, and the temperature to which the oven shall be heated may be adjusted by means of the thermostat according to the calibration of the dial 24.

Since the cam 43, the latch 91 and the thermostat cooperate in the manner previously mentioned herein, the circuit of the resistor element 106 may be energized for a predetermined interval of time, at the end of which the latch 91 is actuated by the cam to the position in which the lever 82 is held to maintain the switch in a circuit-opening position. The resistor element 106 will now remain deenergized until such time as it is desired to cause the circuit thereof to be completed, i. e., by releasing the latch mechanism 91 to that position in which the thermostat is operative to actuate the lever. 82.

It is apparent from the drawings that the temperature-time control device illustrated may be secured to the oven wall, as illustrated, by means of a bracket 111, the bracket being secured to the outer wall of the oven and to the body portion 10, the flange 14 and a bolt 112 extending through the oven wall. The tubular member 25, as shown, extends through an aperture in the oven wall into the oven chamber andis responsive to the temperature of the oven.

Various modifications may be made in the device embodying my invention without departing-from the scope and the spirit thereof. I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art and the appended claims.

I claim'asmy invention:

1. A time-temperature control device comprising a switch, switch-actuating means, "a thermostat for actuating said means and time controlled means for rendering the actuating means operative during a certain portion ofitstravel and inoperative during another portion of said travel, said portions being effective for intervals of time proportional to the total time required for the completion of one cycle of said travel.

2. A time temperature control device comprising a switch, switch actuating means, a thermostat for actuating said means and timing means for rendering the actuating means operative during a certain portion of its travel and inoperative during another portion of said travel, said portions being effective for intervals of time proportional to the total, time required for the completion of one cycle of said travel.

3. A time temperature control device comprising a switch actuable to a plurality of positions, switch-actuating means, means responsive to a condition to be controlled for actuating said means, acam for actuating said actuating means and means for driving said cam at a predetermined speed, said cam being operative during a predetermined por tion of its travel to render the switch inoperative whereby the switch is maintained in one of its circuit controlling positions.

4. The combination with a switch, switchactuating means for controlling the circuitcontrolling positions of said switch, a cam for rendering said actuating means effective during certain intervals of time and inefiective during other intervals, and means for drivin said cam, of means responsive to a condition under'the control of said switch for operating said switch-actuating means during the period in which said actuating means is rendered eiiective.

5. The combination with a switch, switch actuatin'g means for controlling the circuitcontrolling positions of said switch, a cam,

for rendering said actuating means efi'ective during certain intervals of time and ineffective during other intervals, and means for driving said cam, of temperature responsive means for operating the switch-actuating means in accordance with its thermal condition during the period said acuating means is effective.

6. The combination with a switch, switchactuating means for controlling the circuitcontrolling positions of said switch, a cam for rendering said actuating means effective during certain intervals of time and ineffective during other intervals, and means I for driving said cam, of thermostatic means for operating the switch-actuating means in accordance with its thermal condition during the period said actuating means is effective.

7. The combination with motor means, a

cam driven thereby and switch mechanism operable by said cam to a pluralityof circuit-controlling positions in accordance with the travel of said cam, of thermostatic means for actuating the switch mechanism alternately from one to another of said circuitcontrolling positions only during a predetermined portion of the travel of said cam.

8. The combination with a switch, means for actuating said switch to a plurality of circuit-controlling positions, a cam, and means for driving said cam, said cam being effective to hold said actuating means in one position during a portion of its travel and in another position during subsequent portion of travel, whereby said switch is held successively in one or another of its circuit-controlling positions, of a latch operable by said cam for locking the actuating means in a certain position whereby the switch is restrained to one of said circuitcontrolling positions.

9. The combination with a switch, switchactuatin means therefor, a motor, and a cam driven thereby for operating said actuating means, whereby said switch is held in a circuit-interrupting position during a portion of its travel and in a circuit-closing position during another portion thereof, of thermostatic means for operating the switch mechanism during the last-named portion of the travel of said cam, whereby the switch is actuated alternately and intermittently from the circuit-interrupting to the circuitclosing positions.

10. The combination with a switch, actuatin means therefor, a motor, and a cam driven thereby for actuating said means in accordance with the travel thereof, whereby said switch is maintained in a circuit-interrupting position during one portion of said travel and in a circuit-closing position during another portion thereof, of means for adjusting the length of one portion of the travel of said cam relatively to the length of another portion.

11. The combination with a switch, actuating means therefor, a motor, and a cam driven thereby for actuating said means in accordance with the travel thereof whereby said switch is maintained in a circuit-interrupting position during one portion of said travel and in a circuit-closing position during another portion thereof, of means for adjusting the initial position of both portions of the travel of said cam.

12. The combination with a switch for controlling an electric circuit and means responsive toa condition to be controlled for causing said switch to be actuated intermittently to circuit-interrupting and circuitmaking positions of time-controlled means for actuating said switch to the circuit openin'g position only when an interval of time of a predetermined length has elapsed during which said condition has been controlled.

13. The combination with a switch for controlling an electric circuit, thermostatic means and means operable thereby for actuating said switch in accordance-with a condition to be controlled thereby, of a cam, means for driving said cam, and a latch mechanism operable by said cam for locking the switch in a circuit interrupting position after said condition has been controlled for a predetermined interval of time.

14. A time-temperature control device comprising a switch operable to a plurality of positions, a driven member, and means operable by said driven member for maintaining said switch in one of said positions for a predetermined interval of time and in another of said positions during an interval subsequent relatively to the first interval, and thermostatic means for actuating the switch alternately from one to another of its positions during said subsequent interval, in accordance with the thermal condition thereof.

15. A time-temperature control device comprising a switch operable to a plurality of positions, a driven member, means operable by said driven member for maintaining said switch in one of said positions for a predetermined interval of time and in another of said positions during an interval subsequent relatively to the first interval, and means responsive to a condition to be controlled for actuating the switch alternately from one to another of its positions during said subsequent interval.

16. The combination with a switch mechanism of thermostatic means for actuating said switch mechanism to a circuit-interrupting position, a latch and means operable by said thermostatic means for holding the switch in a circuit-interrupting position when actuated thereto by said thermostatic means.

In testimony whereof, I have hereunto subscribed my name this 21st day of April,

AUGUST J. MOTTLAU. 

